2000 Flushes Blue Plus Bleach kills 99.9 percent of bacteria. With a concentrated formula, the automatic toilet bowl cleaner delivers continuous cleaning action for up to four months. It uses powerful chlorine to bleach away stains to keep your toilet bowl continuously sanitary, stain-free & deodorized. 2000 Flushes Toilet Bleach freshens your bowl & keeps the water crystal-clear with every flush. Cleaner is not harmful to plumbing or septic tanks when used as directed.